1. Field of the Invention
The present invention relates to an implantable fixation device for repair of fractures of the olecranon and methods for using same.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
With regard to fractures of the olecranon requiring surgical repair, the traditional approach has been to utilize a plate/screw (see FIG. 1), tension band wiring (see FIG. 2), and/or Kirschner wire (or “K-wires” as they are known; see FIG. 3) fixation technique based upon the type and severity of the fracture. The plate/screw fixation technique is, quite simply, fixation of the fracture through the addition of a precision-designed plate made of surgical-grade alloy to the fracture site, where it is held in place using like-alloy bone screws. Use of plate/screw fixation is typically recommended for comminuted fractures and fractures that occur at or distal to the coronoid process in order to provide sufficient lateral/rotational support to the injury.
In brief, during a typical olecranon fracture repair procedure using existing fixation techniques, an incision is started posteriorly above the patients elbow, and continues distally, curving either ulnarly or radially to avoid the point of olecranon, and is continued distally towards the posterior border of the ulna to a point 3 to 4 cm distal of the fracture. An ulnarly-based incision is preferred primarily because it affords a better exposure of the ulnar nerve, which may need to be transposed anteriorly at the end of the procedure, whereas a radially based incision requires considerable undermining. With the elbow in extension such that the pull of the triceps muscle is relaxed, the fracture site then visualized by elevating the periosteum proximally with proximal fragment. If the fracture involves lateral exposure, the repair requires detachment of the aconeus muscle from the radial side of the ulna. Moreover, if the fracture involves medial exposure, the repair risks damage to the ulnar nerve. The fracture is then properly reduced and held for fixation by using one or more towel clips or K-wires while the area is prepared for fixation. For example, a properly sized plate is chosen to span the fracture and a large number of bone screws are installed. Lag screws are applied at both the proximal and distal ends in divergent positions to increase stability of the repair.
As evidenced by the above repair procedure, the plate/screw fixation technique has numerous attendant problems. For one, a large skin incision is required with the currently offered plate and screw fixation method. This results in extensive dissection of the soft tissues and large amounts of metal retained in the patient. Large plate repairs can also be felt through the thin layer of skin beneath the patient's elbow, and might also cause pain due when pressure is applied to this area or when accidental contact occurs. In fact, it is not uncommon for portions of a plate or screw heads to emerge from the patient's skin in this area.
The tension band wiring fixation technique is primarily for transverse fractures involving less than 50% of the proximal sigmoid notch, and involves the use of surgical grade wire (approximately 18 gauge) in combination with one or more lag screws, if necessary. During surgery, properly sized holes are drilled into the bone near the fracture site, through which the tension band wiring is threaded. The wire is wrapped appropriately to provide sufficient tension, thereby compressing the fracture site to facilitate healing of the fracture. This fixation technique has attendant problems as well. For example, the wire tension can be lost thereby causing the fracture to reopen.
Studies have indicated that combining a plate/screw fixation technique with a tension band improved the stability of the fixation markedly. However, the combination of these approaches results in an even greater amount of implant hardware being installed in an area of a patient's body that has relatively little cushioning due to the thin skin layer surrounding the repair. Moreover, this combination of fixation techniques merely increases the potential for problems because of each technique's aforementioned shortcomings. The invention described herein addresses many of these shortcomings and provides numerous advantages as will be understood by one of ordinary skill in the art after reading and understanding the detailed description.